Secondary Causes of Hypertension

Question 1

primary hyperaldosteronism is from

Answer 1

an adrenal adenoma or bilateral adrenal hyperplasia that secretes excess aldosterone see hypertension and hypokalemia and metabolic alkalosis.

Question 2

why do we not see hypernatremia with primary hyperaldostonism if excess aldosterone should theoretically increase Na, lower K and increase H2O

Answer 2

There’s no hypernatremia or edema despite increased renal absorption because of aldosterone escape where increased HTN results in increased blood volume to kidneys so there’s higher GFR and atrial natriuretic peptide so increased Na excretion and no edema that forms

Question 3

initial evaluation for primary hyperaldosteronism is

Answer 3

morning plasma aldosterone concentration (PAC) to plasma renin activity (PRA) ratio.

Question 4

what is an abnormal PAC/PRA Plasma aldosterone conc / plasma renin activity ratio that would suggest a primary hyperaldosteronism?

Answer 4

PAC/PRA ratio >20 with plasma aldosterone >15 ng/dl This isn’t it though. needs a confirmation test

Question 5

if there’s a positive screening test, what’s the confirmatory test for primary hyperaldosteronism?

Answer 5

needs an aldosterone suppression test.

give IV or oral sodium load and measure aldosterone level later and see if it’s suppressed.

If not suppressed then it’s an aldosteronism excess.

This doesn’t rule out if it’s bilateral metaplasia or adrenal adenoma

Question 6

once primary hyperaldosteronism is confirmed need to figure out if it’s a adrenal adenoma or bilateral adrenal metaplasia and so need

Answer 6

CT imaging and look for adrenal gland abnormalities. NOTE CT scan sucks at picking up small tumors and so needs to get a adenal venous sampling

Question 7

when do you get adrenal venous sampling?

Answer 7

when you’ve confirmed that you have primary hyperaldosteronism but CT scan doesn’t tell you if it’s adrenal adenoma or bilateral adrenal hyperplasia

Question 8

treatment of primary hyperaldosteronism

Answer 8

surgery if it’s a single adrenal adenoma medical therapy with spironolactone or eplerone if its bilateral adrenal hyperplasia

Question 9

what is the pathophysiology for primary hyperaldosteronism and aldosterone escape?

Answer 9

Question 10

if pt has recurrent flash pulmonary edema and atherosclerotic dx and severe hypertension, should think of

Answer 10

renovascular dx due to bilateral renal artery stenosis.

Question 11

Causes of secondary hyperaldosteronism

When the PAC/PRA is not greater than 20

Answer 11

Question 12

features concerning for Renal artery stenosis

Answer 12

atherosclerosis in hx, rapid onset of HTN in pts >55 yrs old with risk factors for atherosclerosis (smoking).

Can also see abrupt increase in Cr after being on ACE, recurrent flash pulm edema, abdominal bruits and asymmetrical renal size on imaging.

Question 13

clinical clues to renovascular disease (chart)

Answer 13

Question 14

treatment for bilateral renal artery stenosis

Answer 14

needs ACE i or ARB. no longer contraindicated but most pts will experience a small decline in glomerular filtration rate

HTN in RAS is caused by RAAS which leads to sodium retention and volume expansion. So the ACEi + diuretic will help with prevention of CKD, decrease risk for MI, stroke, decreased mortality.

It’s as effective as angioplasty in pts

Question 15

in renal artery stenosis who gets stenting?

Answer 15

people who fail optimal medical therapy (refractory HTN, inability to tolerate medications, progressive renal insufficiency)

Question 16

what causes plasma renin levels to be low

what about high?

Answer 16

low:

in primary hyperaldosteronism - high aldosterone and so not trying to hold onto water

suppression of antihypertensives- the meds suppress levels

high sodium diet or bilateral renal artery dx - already has high salt water retention so trying not to hold onto water b/c already has HTN

Can be high

if theres renal renovascular hypertension.

Question 17

Pickering Syndrome

Answer 17

bilateral renal artery stenosis pts can have flash pulmonary edema despite normal LV EF.

Question 18

how to evaluate for renal artery stenosis?

Answer 18

renal doppler ultrasound and CT or MR angiography

Question 19

HTN factors that should make one consider renovascular dx?

Answer 19

resistant HTN (uncontrolled despite 3 drug regimen)

malignant HTN (w/ end organ damage)

Onset of severe HTN>180/120 after age 65

severe HTN with diffuse atherosclerosis

recurrent flash pulmonary edema with severe HTN

Question 20

physical exam: asymmetric renal size >1.5 cm, abdominal bruit

lab results: unexplained rise in Cr >30% after starting an ACEi or ARB

imaging results: unexplained atrophic kidney

Answer 20

renovascular dx

Question 21

when should spirolactone and eplerenone be stopped prior to screening?

Answer 21

Stop 6 weeks prior to screening for primary hyperaldosteronism (aldosterone/renin) because these can affect interpretation of labs.

Question 22

what to do if there’s an incidental adrenloma?

Answer 22

Question 23

fibromuscular dysplasia is

Answer 23

see twisting and beading of the renal artery. presents with HTN in young female

CT angiography or ultrasound with dopplers is ok to use.

management: ACEi or ARB o r angioplasty

Question 24

hypertension, metabolic alkalosis, hypokalemia

Answer 24

think: primary hyperaldosteronism.
testing: stop diuretics to assure euvolumia

get PAC/PRA ratio >20 is positive

confirmatory testing: oral or IV salt loading and fludrocortisone suppresion and captopril challenge tests.